Dust in my lenses

I recently noticed a few dust managed to get inside my 35L. I don't think I can remove them by usual means. As far as the IQ is concerned, I see no difference. From my knowledge, these kind of dust should not affect the image and performance of the lens. Right ?

Should I turn the lens to service as it is still under warranty ? I afraid this introduce more dust / trouble, you know the skill of Canon service nowadays.